Question
If an $AC$ main supply is given to be $220\,V$. The average $emf$ during a positive half cycle will be.....$V$
✓
Answer
$\mathrm{E}_{\mathrm{rms}}=220 \mathrm{V}$
$\therefore \mathrm{E}_{\mathrm{rms}}=\frac{\mathrm{E}_{0}}{\sqrt{2}} \Rightarrow \mathrm{E}_{0}=\sqrt{2} \mathrm{E}_{\mathrm{rms}}$
Average e.m.f over half cycle
$=\frac{2}{\pi} \mathrm{E}_{0}=0.637 \times 1.41 \times 220=198.15 \mathrm{\,V}$
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